The problem of negative impact on the environment of motor transport is one of the most fundamental in the complex of global problems. The constant increase in the number of cars with internal combustion engines encourages the search for methods and ways to reduce the volume of negative impulses. The operation of heat engines is accompanied by significant emissions of gaseous harmful substances into the atmosphere, i.e. nitrogen oxides, carbon monoxide, hydrocarbons, as well as solid particles, including soot. The solution to this problem should be implemented within the framework of a systematic approach. To do this, it is necessary to combine the study of technical, economic, and organizational approaches to the organization of the exhaust gas disposal process. To date, there is a significant methodological base in the field of organizational and economic decisions. The article discusses various methods of cleaning exhaust gases of piston engines, their advantages and disadvantages are noted. The method of processing using ammonia is widely known. It is noted that a catalytic method for reducing nitrogen oxides using ammonia is quite economical. However, the optimal temperature range at which nitrogen oxides are reduced is rather narrow. To solve this problem, it is proposed to use the vortex effect in the exhaust system. The efficiency of using a vortex gas recirculation pipe is due to its significant influence on the thermal gasdynamic processes occurring in the exhaust system. Using the principles of non-equilibrium thermodynamics allows us to take into account dissipative processes when establishing the relationship of fuel and economic indicators of internal combustion engines with thermodynamic parameters. This significantly increases the accuracy of calculations and allows you to develop measures to reduce the level of negative impact on the environment.

Resource-saving technologies are now actively used in the field of piston design. The modernization of internal combustion engines should be based on evaluation of the efficiency. The development of new methods for assessing the thermodynamic efficiency of heat use in piston engines is an essential part of improving the efficiency of motor vehicles. At present, when assessing the efficiency of thermodynamic processes in internal combustion engines of the indicator efficiency, the essence of the process of converting the thermal form of energy into mechanical work is not considered. In this regard, there is a need to study the working processes of piston engines to develop a more advanced method. The article proves the prospects of using the entropy approach and variational principles of nonequilibrium thermodynamics. This method is based on the first and second laws of thermodynamics, and allows taking into account not only the quantity, but also the quality of energy. The differential equation of thermal balance of the engine taking into account heat dissipation in the engine is offered. This equation assumes establishment of functional dependence of production of entropy in systems on parameters of the irreversible thermodynamic processes proceeding in it, and also search of optimum of the received objective function. The proposed method of entropy analysis of nonequilibrium thermodynamic processes in piston engine systems allows to evaluate the degree of efficiency of each system and to investigate the maximum capabilities of the piston engine. As a result of using the proposed method, heat losses in the engine systems are reduced.